Adjustable ladder



Dec. 22, 1942. Q Q'BERMEYER 2,305,985

ADJUSTABLE LADDER Filed May 29, 1941 3 Sheets-Shea}. l

INVENTOR.

A TTORNEYS.

Dec. 22, 1-942.

E. c. OBERMEYER 2,305,985

ADJUSTABLE LADDER Filed May 29, 1941 3 Sheets-Sheet 3 z. a axe/1mg e2 INVENTOR.

A TTORNEYS.

Patented Dec. 22, 1942 UNITED STATES PATENT OFFICE 12,305,985 'ADJUSTABLELADDER Edward C. Obermeyer, Grand. Rapids, Mich. 1ApplicationfMay'29', 1941,"Seria1:No..:395;865

.5 Claims. (Cl. 228-163) The device forming the subject matter oithis application is a step ladder, adapted 'forindoor use or for outdoor use, novel means being provided for holding the legs of the ladder at adjusted' lengths, so that the ladder will stand upright, even though the underlying supporting surface maybe verticaly irregular.

It is Within the province of the disclosure to improve generally and to enhance the utility of devices of that type towhich the present invention appertains.

With the above and other objects in view, which will appear asthe description proceeds, the invention resides in the combination andarrangement of parts andiin the details of .construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed, may be made within the scope of what is claimed, without departing from the spirit of the invention.

.In the accompanying drawings:

Fig. 1 shows, in front elevation, a step ladder constructed in accordance with the invention;

Fig. 2 is a side elevation of the step ladder;

Fig. 3 is a fragmental vertical sectional- View, disclosing one of the grips and associated parts;

Fig. 4. is a transverse-section of Fig. 3;

Fig. 5 is a transverse section on the line'- 5-'-5 of Fig. 1; r

Fig. 6 is a front elevation illustrating one of the many positions which the parts of the ladder may assume, when it is used .on an irregular surface; 1 Fig. 7 is a sectional detail disclosing'one of the spacers :and attendant parts;

Fig. 8 is a'frontelevation showing amodified form;

Fig. '9 i=sa front elevation of the ladder delineated in Fig. 8, the parts being arranged as they will appear when the ladder is set up on an irregularsurface;

Fig. 10 is'a s-ide-'elevation of the ladder "shown in Fig. 8;

'Fig. 11 isa vertical sectionalview disclosing'details of one of the leg structures;

Fig. 12 is a transversesection .on l2-I2 of Fig. 11;

Fig. 13 is a transverse section von the line [3-13 ofFigHQ;

Fig. '14; is asectional elevation-showing one of the grips and associated parts.

Figures -1 to 7 disclose a ladder adapted primarily zbutmotnecessarily for indoor use. The ladder includes sarplatform I. '1 The rear legs-:or

th .line

prop of the ladder .are designated generally by the numeral 2.

The rear legs .2 comprisellpper sections 3, which are hinged. at .4 to the platform I.. The upper sections 301? the rear legs .carry the usual foldable tool support 5. :The upper sections 3 are connected .by cross braces .6.

The. lower sections "I .of'the rear legs .2 are disposed inwardly .of the upper sections'3. The lower sections lmay berubber shod, as shown at18.

"Guides 9, which are u-shaped, are secured to thelower sections 1, and .U-shaped' brackets I!) are secured .to the upper .sections '3. The upper sections '-3 are islidably mounted in the guides 9, and the lower sections I are slidably mounted in the brackets -I 0.

.Figures Band 4 show that .cam .lever grips II are pivotally mounted at I2in the brackets Ill. Pull springs l4 .connect the grips II with the upperJegsections 3 and .cause the grips II to bindxthelowerileg sections 3 and i together against relative longitudinal sliding movement.

Theiforward .legs of the ladder are designated generally.by:the.numeral I5 and form a tread member. The forward legs I5 include upper sections 15, which are hinged at H to the platform I. .There are spacers I9 on the :outer surfaces of the upper leg sectionslfi. The spacers -l9.have.openings I0 which receive the heads of bOltS'ITl that retainptreads I8 between the leg sections I6. Guides 20, of U-shape, are securedto the upper leg sections IS.

The lower sections of the forward legs I5 are marked by thenumeral 2|. They are disposed outwardly of the upper sections I6 and can slide foradjustment inthe guides20, in contact with the spacers I9.

The numeral22 designates a lever of the first order,;f ulcrumed at 23, intermediate its ends, on one 'of the treads I8. Links 24 are provided, and .are'pivotedat 25 to the ends of the lever 22 and to the lowerends of the sections 2 I.

Referring to Fig. 5, hook-shaped grips 26 extend in opposite directions around the leg sections 2| -and I6. The grips 2B are pivotally mounted, at 21, intermediate their ends, .on the upper leg sections IS. The grips 26 include inwardly projecting handles 28 located behind one of the treads I8. Pull springs 29 are connected to the handles 28 andto the upper sections I6 of the forward legs I5.

.By slacking away the cam lever grips ll of Fig. :3, either or ,both of the lower sections 1'! of therear legs 2 maybe adjusted .upordown, and

when the grips are released by an operator, the pull springs |4 cause the grips to bind the leg sections 3 and 1 together, thereby holding the rear legs 2 at any lengths to which they may have been adjusted.

By means of the handles 28, the hold of the grips 26 may be released, and one or both of the lower front leg sections 2| may be moved upwardly or downwardly. When the handles 28 are released by an operator, the springs 29 react and cause the grips 26 to bind the leg sections l and 2| tightly together, thereby holding the leg sections 2| at any height to which they may have been adjusted.

The lever 22 and the links 24 cause the lower sections 2| of the forward legs |5,- each, to move upwardly when the other leg section moves downwardly, an observation which will be understood readily when Fig. 6 is noted. The construction is such that the ladder can be used even though" there are many irregularities in the supporting surface.

Notwithstanding the fact that the leverv 22 automatically adjusts the effective lengths of the leg sections 2| when there are irregularities in the surface of the soil, the soil may bemore yielding beneath one leg section than beneath the other, and the operator may wish to assure himself, before he ascends the ladder, that it will maintain an upright and proper position under his weight. It will be noted that the endportions of the lever 22 extend outwardly and laterally beyond the leg sections 2| to serve as members upon which he may throw his weight, thereby advancing one leg section into the ground until it comes to a firm seat.

Passing to the form depicted in Figs. 8 to 14, there is shown a step ladder adapted primarily but not necessarily for outdoor use.

The ladder comprises a platform 30, a rear leg or prop being designated generally. by the numeral 3|. The numeral 32 marks the downwardly converging members of the upper section of the rear leg 3|. The parts 32 of the upper leg section are hinged as shown at 33 to the platform 30.

At their lower ends, the downwardly converging members 32 of the upper section of the rear leg 3| are joined together by straps 34, which define a lower guide.

Above the straps 34, the downwardly converging members 32 of the upper leg sectionxare connected by straps 35, which define an upper guideway. Adjacent to one .of the members 32 of the upper leg section, a filler block 35 is secured between the straps 35, as shown in Figs. 11, 12 and 14. I

The member 32 (Figs. 12 and 14) of the upper leg section which is remote from the filler block 36, is received within the forkedhead 31 of an inwardly projecting grip 38, the head of the grip being pivoted at 4| to the aforesaid member 32. The grip 38 is drawn upwardly by a pull spring 39, the lower end of the spring being secured to the grip 38, and the upper end of the spring being secured to the adjacent member 32 of the upper leg section. An upright releasing lever 40 is fulcrumed intermediate its'ends, at 42, on the straps 35, the lower end of the releasing lever bearing on the grip 38. V

The numeral 43 marks a lower leg section, mounted for vertical adjustment in the lower guideway formed by the straps 34, and in the space between the straps 35, in contact'withthe filler block 36. Under the impulse of the spring 39, the grip 38 bears against the lower leg section 43 and holds it in any position to which it may have been adjusted vertically, it being possible to release the hold of the grip 38 on the lower leg section 43, by manipulating the lever 49.

A forward leg structure or tread member is provided, and is designated generally by the numeral 5|. The forward leg structure 5| embodies parallel stiles 52, connected by treads 53. The stiles 52 are hinged at 54 to the platform 30. The members 32 of the rear leg structure, and the stiles 52 of the forward leg structure are joined together by cross rods 56, a rule joint brace 55 extending between the cross rods.

I Radius arms 51 are hinged at 58 to the outer sides'of the stiles 52, for lateral swinging movement. .Lower leg sections 59 are supplied, and

are equipped at their upper ends with guides 60,

wherein the radius arms 51 are received slidably. At their lower ends, the radius arms 51 are equipped with guides 6|, wherein the lower leg sections 59 are slidably received.

Brackets 12 of U-shape are secured to' the radius arms 51 and receive the lower leg sections 59 slidably. Grips 62 of U-shape are provided, and are pivotally mounted at 63v within the brackets 12. The grips 62 have inwardly projecting handles 64, which extend past each other at their inner ends, and are located behind one of the treads 53. The upper ends of pull springs 65 are connected to the handles 64 of the grips, the lower ends of the springs being connected to the stiles 52. The tendency of the springs 55 is to cause the grips 62 to press the radius arms 51 and the lower leg sections 59 together, thereby holding the parts 51 and 59 against relative longitudinal movement.

In order to lengthen the effective height of the rear leg structure 5|, the releasing lever 40 is manipulated, thereby breaking the hold of the grip 38 on the lower leg section 43, it being possible to adjust the lower leg section vertically.

When the lever 40 is set free, the grip 38 resumes its hold on the leg section 43, responsive to the spring 39.

By manipulating the grips 62, through the instrumentality of the handles 64, the lower leg sections 59 maybeset free for longitudinal adjustment.

The numeral 44 designates a lever of the first order, fulcrumed intermediate its ends, at 45, on one of the treads 53 that connect the stiles 52. The lever 44 is pivoted at its ends, as shown at 41, to the lower leg sections 59.

The lever 44 constitutes a brace connectionbetween the leg sections '59, of such nature that when one of the leg sections is slid upwardly, the other leg section will be slid downwardly, without attention on the part of the operator, the lever 44 automaticallyfixing the spread of the lower sections 59. v

The device forming the subject matter'of this application will be found thoroughly effective, in either of its forms, to consummate the objects set forth in the opening portion of the specificato the operation grip extended about the upan inwardly-projecting releasing handle, means for fulcruming each grip intermediate its ends on one of the upper sections, and spring means constraining each grip to bind the upper and lower sections of one pair together, against relative longitudinal movement.

2. A step ladder comprising a platform, a prop hinged to the platform, a tread member hinged to the platform and comprising upper and lower sections assembled for relative longitudinal sliding adjustment, a lever fulcrum-supported intermediate its ends on the upper sections, pivoted links connecting the ends of the lever movably to the lower sections, to cause each lower section to move upwardly when the other lower section is moved downwardly, and mechanism for releasably holding each lower section against longitudinal movement with respect to the corresponding upper section, the lever comprising end portions which extend outwardly and laterally beyond the sections to serve as members upon which the operator can throw his weight to adjust the effective length of either section, should the soil be more yielding beneath one section than beneath the other.

3. A ladder comprising upper leg sections, treads disposed between the sections, securing devices connecting the treads with the sections and having heads disposed outwardly of the sections, spacers secured to the outer surfaces of the sections and defining openings receiving the heads, the spacers being at least as thick as the heads, lower leg sections, means for mounting the lower leg sections for longitudinal sliding movement on the spacers, said means being secured directly to the upper sections, and independently of the spacers, whereby the spacers may be renewed without disturbing said means, the spacers constituting wear strips and serving to space the lower sections the more widely apart, thereby to increase the stability of the ladder, and prop means assembled with the upper sections.

4. A ladder comprising a tread member including upper and lower sections assembled for relative longitudinal sliding adjustment, a lever fulcrum-supported intermediate its ends on the upper sections, pivoted links connecting the ends of the lever movably to the lower sections, to cause each lower section to move upwardly when the other lower section is moved downwardly, and mechanism for releasably holding each lower section against longitudinal movement with respect to the corresponding upper section, the lever comprising end portions which extend outwardly and laterally beyond the sections to serve as members upon which the operator can throw his weight to adjust the effective length of either section, should the soil be more yielding beneath one section than beneath the other.

5. A ladder comprising a tread member including pairs of upper and lower sections, the members of each pair being sli-dably assembled for longitudinal adjustment, a hook-shaped grip extended about the upper and lower sections of each pair and including an inwardly-projecting releasing handle, means for fulcruming each grip intermediate its ends on one of the upper sections, and spring means constraining each grip to bind the upper and lower sections of one pair together, against relative longitudinal movement.

EDWARD o. OBERMEYER. 

